The invention arose primarily out of the needs and concerns associated with space based radiators which reject large amounts of heat from spacecraft power plants. Radiator designs for rejecting heat from space-based power plants place a premium on weight savings, survivability and launch volume. Preferably, the radiators will be flexible for folding or rolling into a small launch volume. The radiator would be expanded in space. Flexible radiators offer benefits such as adaptability to variable heat load, and are retractable when not in use to enhance survivability.
Such features have already been incorporated into flexible heat pipes and other radiators, but it is not clear at this time if such concepts will truly be workable in a space environment. For example, Merrigan et al., PROC-849453, "Heat Pipe Technology Development for High Temperature Space Radiator Applications," a paper presented at the Proc. 19th Intersociety Energy Conversion Engineering Conference in 1984, teaches the use of flexible, segmented metal heat pipes for high temperature space radiator applications. Ponnappan et al., "Conceptual Design of a 1 m Long `Roll Out Fin` Type Expandable Space Radiator," a paper presented at the AIAA/ASME 4th Joint Thermophysics and Heat Transfer Conference in 1986, discloses an expandable roll out radiator comprised of two thin walled sheets sealed along their edges and formed into a spiral coil. The roll out fin is stated as being manufactured from either a thin metallic foil 51 microns thick or a plastic film with a coil spring. Chow et al., "Fluid Recirculation, Deployment and Retraction of an Expandable Pulse Power Radiator," a paper also presented at the 1986 Trans. AIAA/ASME 4th Joint Thermophysics and Heat Transfer Conference, discloses a radiator made of a low-density, thin flexible material that can be collapsed and stored in a compact form and can be expanded readily when high peak power heat loads are imposed.
This invention is directed to improvements over the above and other prior art space radiator materials. However, as will be described below, the technology of the invention will be applicable in other space and terrestrial applications.